| Title | Fluid-injection-induced earthquakes characterized by hybrid-frequency waveforms manifest the transition from aseismic to seismic slip |
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| Author | Yu, H ;
Harrington, R M; Kao, H; Liu, Y; Wang, B |
| Source | Nature Communications 12, 6862, 2021 p. 1-11, https://doi.org/10.1038/s41467-021-26961-x  Open Access |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20210336 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf; html |
| Province | British Columbia |
| NTS | 93O; 93P; 94A; 94B; 94G; 94H |
| Area | Fort St. John; Dawson Creek |
| Lat/Long WENS | -124.0000 -120.0000 58.0000 55.0000 |
| Subjects | geophysics; Science and Technology; Nature and Environment; fossil fuels; Economics and Industry; seismology; seismicity; seismic risk; earthquakes; earthquake risk; earthquake magnitudes; seismic
waves; petroleum industry; hydrocarbon recovery; hydraulic fracturing; bedrock geology; structural features; faults; pore pressures; stress analyses |
| Illustrations | location maps; seismograms; 3-D diagrams; times series; geoscientific sketch maps; plots |
| Program | Environmental Geoscience Shale Gas - induced seismicity |
| Released | 2021 11 25 |
| Abstract | Aseismic slip loading has recently been proposed as a complementary mechanism to induce moderate-sized earthquakes located within a few kilometers of the wellbore over the timescales of hydraulic
stimulation. However, aseismic slip signals linked to injection-induced earthquakes remain largely undocumented to date. Here we report a new type of earthquake characterized by hybrid-frequency waveforms (EHWs). Distinguishing features from typical
induced earthquakes include broader P and S-pulses and relatively lower-frequency coda content. Both features may be causally related to lower corner frequencies, implying longer source durations, thus, either slower rupture speeds, lower stress drop
values, or a combination of both. The source characteristics of EHWs are identical to those of low-frequency earthquakes widely documented in plate boundary fault transition zones. The distribution of EHWs further suggests a possible role of aseismic
slip in fault loading. EHWs could thus represent the manifestation of slow rupture transitioning from aseismic to seismic slip. |
| Summary | (Plain Language Summary, not published)
Felt earthquakes can be induced a few kilometers away from the hydraulic fracturing injection site, yet how the physical triggering mechanism of the
rupture process is largely unknown. In this paper, we report a new type of earthquakes with unique waveform characteristics. These earthquakes have roader P and S-pulses and relatively lower-frequency coda content, and are named "earthquakes
characterized by hybrid-frequency waveforms" (EHWs). Compared to ordinary earthquakes, EHWs generally have either slower rupture speeds, lower stress drop values, or a combination of both. The source characteristics of EHWs are identical to those of
low-frequency earthquakes widely documented in plate boundary fault transition zones. Thus, EHWs probably represent the manifestation of slow rupture transitioning from aseismic to seismic slip. |
| GEOSCAN ID | 329000 |
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